Method for Repairing and/or Checking an in Particular Refrigerating Installation Accommodated in a Tank Which is Closed in a Pressure-Tight Manner, and Tank for Implementing the Method

ABSTRACT

Method for repairing and/or checking a refrigerating installation accommodated in a tank which is closed in a permanently pressure-tight manner, includes the steps of cutting the tank open at at least one predetermined severing location, repairing and/or checking the installation located in the tank, and closing the tank at the severing location by an integral connection.

TECHNICAL FIELD

The present invention refers to the field of installation engineering.It refers to a method for repairing and/or checking in particular arefrigerating installation accommodated in a tank that is closed in apressure-tight manner. It further refers to a tank for carrying out saidmethod.

PRIOR ART

It has been known for a long time (see, e.g., WO 2004/020918 A1 or WO2009/094788 A1) to structure high-power refrigerating installations in amodular manner so as to be able to respond flexibly and efficiently todifferent demands in terms of consumption for refrigeration. In doingso, the refrigerating installations are to be composed of usuallysimilar refrigerating modules, each of which are encased by a protectivecasing in such a manner that protection between the refrigerationcircuit of the individual module and the environment is provided. Thisprotection absorbs refrigerant potentially leaking from therefrigeration circuit and prevents harmful contact between therefrigerant and the environment.

A greatly simplified diagram of such a modular refrigeratinginstallation is represented in FIG. 7. The refrigerating installation 40shown there is composed of a plurality of refrigerating modules KM1 . .. KMn that operate in parallel and each have a local refrigerationcircuit with a compressor 38 and a heat exchanger 16. From the heatexchanger 16 of each refrigerating module KM1 . . . KMn, connectinglines are fed to the collecting lines SL1, SL2, which, for example,connect the individual modules to a refrigerating load.

Each of the individual refrigerating modules KM1 . . . KMn is now to beaccommodated in a tank 10 that is closed in a pressure-tight manner andhas an internal pressure (e.g. a vacuum) that differs from the outside.Such a tank that is closed in a pressure-tight manner for eachrefrigerating module has the followings effects:

-   -   It ensures that in the case of leakages, no refrigerant can        escape into the environment. In the case of a leakage, it shall        be possible to recover the refrigerant (optionally to dispose or        recycle it).    -   If the refrigerant is in particular poisonous, danger to humans        and animals, etc. can be ruled out without the need of further        measures.    -   If the refrigerant is in particular flammable or explosive,        danger to humans and animals, etc. can be ruled out without the        need of further measures.    -   The same applies to all other types of danger to the        environment, in particular to humans and animals (e.g.,        pressure, greenhouse effect).    -   If there is a vacuum in the casing, this results in further        advantages:        -   Leaking refrigerant is possibly recyclable.        -   Additional thermal insulation is not required.        -   In the case of leaking refrigerant, the installation can be            turned off immediately by means of a pressure sensor, and an            alarm can be output.        -   In the case of a defective casing and/or tank, likewise, a            pressure increase takes place (or a pressure drop, in the            case of a previous overpressure), which can turn off the            installation immediately and can output an alarm.    -   The casing and/or the tank can absorb and dampen vibrations and        noise.    -   The casing and/or the tank provide protection against mechanical        damage.    -   The interior of the casing and/or the tank can be cooled (if        heat dissipation of the compressor becomes a problem, the        interior can be kept at a desired temperature by means of tube        coils or the like, e.g., by the cold return temperature or flow        temperature of the medium, or by corresponding measures).

However, it is also conceivable that the casing and/or the tank isfilled with a protective gas (same type of alarm as above).

The casing and/or the tank can have different designs (round,rectangular, cylindrical etc.) and can be made of different materials(stainless steel, steel, carbon, plastic, etc.), which fulfill thementioned properties.

The tank with the module can be built as a vertical or horizontaldesign.

In addition to the known advantages of modular technique, the tank hasthe advantage that there might be no restrictions or fewer restrictionswith regard to the installation site (indoor, outdoor, open to public,wall, floor, ceiling, etc.).

No specific structural safety measures are required.

No incorrect (not even unintentional) operations can take place sincethe entire refrigeration circuit is hermetically or semi-hermeticallysealed.

In the case of damage, the modules can be replaced or can be repaired byadequate qualified personnel in an adequate environment.

The problem here is the permanent leak tightness of the tanks with themodules accommodated therein. If the tank is provided with openings thatcan be opened and closed again, which can be opened for repair work oran inspection, seals are required for sealing the openings. However, inorder to maintain a vacuum over a long time period (>10 years),conventional rubber or plastic seals (O-rings etc.) are not sufficientdue to the diffusion problems associated therewith. On the other hand,the use of metal seals is usually expensive.

The invention illustrated hereinafter therefore assumes that the modulesare accommodated in tanks that are permanently closed in a gas-tightand/or pressure-tight manner.

The goal is to build such a containment tank, which shall be gas-tightunder vacuum and pressure (or only pressure), in a cost-effectivemanner, and in the case of repair work, it shall also be possible tocarry this out in a cost-effective manner.

PRESENTATION OF THE INVENTION

It is therefore an object of the invention to provide a method forrepairing and/or checking in particular a refrigerating installationthat is accommodated in a tank that is closed in permanentlypressure-tight manner, which method can be carried out in a simple andsafe manner, and wherein permanent tightness is also ensured after therepair work or check.

Furthermore, it is an object of the invention to provide a tank, inwhich in particular a refrigerating installation is accommodated, forcarrying out the method according to the invention.

This and other objects are achieved by the features of the claims 1 and15.

With the method according to the invention for repairing or checking arefrigerating installation accommodated in a tank that is closed in apermanently pressure-tight manner, the tank is cut open at at least onepredetermined severing location, the installation accommodated in thetank is repaired and/or checked, and subsequently, the tank is closedagain at the severing location by means of a firmly bonded connection.

One configuration of the method according to the invention ischaracterized in that by cutting open the tank, the tank is cut into atleast two separate tank parts, and that after repairing theinstallation, the at least two separate tank parts are connected to eachother again in a firmly bonded manner.

Preferably, the at least two separate tank parts are welded together.

Another configuration of the method according to the invention ischaracterized in that from the installation accommodated in the tank, atleast one tube is fed outward through the tank wall, that for feedingthrough the at least one tube, the tank has a tube socket that protrudesoutward from the tank wall and through which the at least one tube isfed outward, and the outside of said tube is connected to the outer endof the tube socket in a pressure-tight manner, that for repairing and/orchecking the installation, the tube socket with the tube placed thereinis cut through at a first predetermined severing location, and thatafter the repair work and/or check, the tube socket is closed again in apressure-tight manner by a firmly bonded connection with the pipe fedtherethrough.

In particular, the at least one tube is connected by a weld on theoutside of the tube in pressure-tight manner to the outer end of thetube socket, wherein after the repair work and/or check, the tube socketis closed again in a pressure-tight manner by welding it to the tube fedtherethrough.

Another configuration of the invention is characterized in that the atleast one tube is cut through at a second severing location positionedoutside the first severing location, thereby forming a gap in the tube,that for closing the gap after the repair work and/or check, the cut-offtube coming out of the tank is first moved outward through the tubesocket such that it adjoins, at the second severing location, the tubepart located on the outside, that then the two ends of the tube areconnected to each other, and that the tube socket is closed again in apressure-tight manner by a firmly bonded connection with the tube fedtherethrough.

Preferably, the two ends of the tube are connected to each other by aweld.

According to another configuration, the at least one tube is connectedto an installation part arranged in the tank, and the tube is displacedtogether with the installation part.

A further configuration of the method according to the invention ischaracterized in that the at least one tube is cut through at a secondsevering location positioned outside the first severing location and ata third severing location inside the tank, thereby forming a gap, thatafter the repair work and/or check, a suitable tube piece is insertedinto the gap for closing said gap and is connected at the second andthird severing locations to the ends of the tube, and that the tubesocket is closed again in a pressure-tight manner by a firmly bondedconnection with the inserted tube piece.

Preferably, the tube piece is connected to each of the ends of the tubeby a weld.

Yet another configuration of the method according to the invention ischaracterized in that on the tank, an outward-facing flange connectionis arranged that has a flange which is closed by a cover attachedthereon, that the flange connection is surrounded by a cap which isfastened to the flange connection and closes the flange connection in apressure-tight manner with respect to the outside, that for repairingand/or checking the installation accommodated in tank, the cap is cutopen at a severing location, and that after completion of the repairwork and/or check, the cap is fastened again to the flange connection ina pressure-tight manner.

A further configuration is characterized in that the flange is spacedapart from the tank wall, that a socket extending towards the tank isattached to the flange, that the cap pulled over the flange connectionand the socket is connected to the free end of the socket in a firmlybonded manner, and that the connection point is severed at the severinglocation by simultaneously cutting through the cap and the socket.

However, it is also conceivable that the flange is spaced apart from thetank wall, that between the flange and the tank wall, a flange ring isattached that extends parallel towards the flange, that the cap pulledover the flange connection is connected to the outer edge of the flangering in a firmly bonded manner, and that the connection point is severedat the severing location by simultaneously cutting through the cap andthe flange ring.

Preferably, the cap is connected to the flange connection by a weld, andafter completion of the repair work and/or check, the cap is fastenedagain by a weld in a pressure-tight manner to the flange connection.

The tank according to the invention, comprising in particular arefrigerating installation accommodated therein, for carrying out themethod according to the invention is characterized in that the tank isclosed in a gas-tight and/or pressure-tight manner by means of firmlybonded connections between its parts.

One configuration of the tank according to the invention ischaracterized in that from the installation accommodated in the tank, atleast one tube is fed outward through the tank wall and that for feedingthrough the at least one tube, the tank has a tube socket that protrudesoutward from the tank wall and through which the at least one tube isfed outward, and the outside of the tube is connected to the outer endof said tube socket in a pressure-tight manner.

In particular, the at least one tube is connected by a weld on theoutside of the tube in a pressure-tight manner to the outer end of thetube socket.

Another configuration of the tank according to the invention ischaracterized in that on the tank, an outward-facing flange connectionis arranged that has a flange which is closed by an cover attachedthereon, and that the flange connection is surrounded by a cap which isfastened to the flange connection and closes the flange connection in apressure-tight manner with respect to the outside.

A further configuration is characterized in that the flange is spacedapart from the tank wall, that a socket extending towards the tank isattached to the flange, and that the cap pulled over the flangeconnection and the socket is connected to the free end of the socket ina firmly bonded manner.

Another configuration is characterized in that the flange is spacedapart from the tank wall, that between the flange and the tank wall, aflange ring is attached that extends parallel towards the flange, andthat the cap pulled over the flange connection is connected to the outeredge of the flange ring in a firmly bonded manner.

Preferably, the cap is connected to the flange connection by a weld.

BRIEF DESCRIPTION OF THE FIGURES

The invention is explained in more detail hereinafter by means ofexemplary embodiments and with reference to the drawing. In the figures:

FIG. 1 shows a sectional view of an example of a permanently closed tankwith a heat exchanger arranged therein and with tubes fed to theoutside, wherein the tank is welded together at the severing locationsfrom a plurality of parts;

FIG. 2 shows how the tank is opened for repairing and/or checking theinstallation (heat exchanger) accommodated therein, according to anexemplary embodiment of the invention, wherein a portion of the tank issevered at a severing location;

FIG. 3 shows a tank with an installation accommodated therein accordingto another exemplary embodiment of the invention, with a specificallyformed flange connection and specifically formed tube feedthroughs (FIG.3( b)), and how the tank is opened at a tube feedthrough (FIG. 3( c));

FIG. 4 shows a different way of opening (FIG. 4( a)) the tank at thetube feedthrough according to FIG. 3, and of closing it again (FIG. 4(b)) by feeding in the tube;

FIG. 5 shows a further way of opening (FIG. 4( a)) the tank at the tubefeedthrough according to FIG. 3, and of closing it again (FIG. 4( b)) byinserting a tube piece;

FIG. 6 shows another exemplary embodiment of the flange connection onthe tank (FIG. 6( a)), and the way of opening and closing it (FIG. 6(b)); and

FIG. 7 shows a greatly simplified diagram of a modularly structuredrefrigerating installation in which the individual modules areaccommodated in each case in a permanently closed tank.

WAYS OF CARRYING OUT THE INVENTION

The center of the invention, according to FIG. 1, is a tank 10 which isclosed in a permanently pressure-tight and/or gas-tight manner by meansof firmly bonded connections between the parts of the tank, and whichcomprises in its interior 11 an installation, in particular forrefrigerating (e.g., a refrigeration circuit), of which a heat exchanger16 is exemplary illustrated in FIG. 1. The tank 10 is built from two (ormore) tank parts 12, 13, and after mounting the installation or themodule or the like, is connected over its circumference in a firmlybonded manner at one or more severing locations 14, 15. In the case ofrepair work or when checking the installation accommodated in theinterior 11, which requires access to the “inner workings”, the tank issevered or cut open, for example, at the severing location 15 (FIG. 2),and after completed repair work and/or checking, is closed again.

It is most suitable with regard to tightness and stability to weld orbraze the tank parts 12, 13 at the severing locations 14, 15, thus toclose them by a metallic bond (however, the materials of the tank 10 areusually not exclusively steel or stainless steels).

The heat exchanger 16 of FIGS. 1 and 2 has tubes 17, 18 that are fedfrom the heat exchanger 16 through the wall of the tank 10 to theoutside so as to be connected, for example according to FIG. 7, tocommon collecting lines SL1, SL2. In the example of FIGS. 1, 2, thetubes 17, 18 are fastened and sealed directly at their feedthroughthrough the tank wall by welds 19 and 20, respectively.

However, in order to be able in the case of repair work or wastedisposal to access the “inner workings” of the refrigerating module(heat exchanger 16) and to disassemble it, if needed, a weld seamdirectly on the tank wall is not practicable since accessing this weldseam is very difficult.

Thus, for feeding the tubes 17 and 18 through the tank wall according toFIG. 3, advantageously, tube sockets 21, 22 protruding outward from thetank wall are provided. By first welding the tube sockets 21, 22 to thetank 10 and feeding the tubes 17, 18 of the installation parts (heatexchanger 16, etc.) accommodated in the interior 11 through these tubesockets 21, 22 and subsequently welding them together at the end of thetube sockets (welds 19 and 20), it is then possible in the event of arepair to cut open the external tube socket 21 and the tube 17 that isaccommodated therein and runs to the heat exchanger 16 by means of acutting disc or a similar tool or method at a predefined severinglocation 23 (FIG. 3( a, c)) and to remove and reinstall the heatexchanger 16 in a simple manner. Subsequently, the tube 17 and the tubesocket 21 are connected again by a new (recessed) weld 19′ (FIG. 3( c))at the severing location 23 in a firmly bonded and pressure-tightmanner.

If by a cut through the tube 17, a gap L according to FIG. 4( b) isgenerated in the tube at a second severing location 23′ located fartherout, the heat exchanger 16 can be “pushed forward” according to FIG. 4(b), and the still remaining shorter line of the heat exchanger 16 can bewelded again to the on-site line (weld 19″) and the (shortened) tubesocket 21 (weld 19′).

However—if it is not intended to push the heat exchanger 16 forward—itis also conceivable (FIG. 5) to make cuts at three severing locations23, 23′ and 23″ of the tube (FIG. 5( a)), thereby creating a gap L′.This gap is closed again later by inserting a corresponding tube piece34 that is connected by welds 33 and 33′ to the remaining tube ends, andto the shortened tube socket 21 by a weld 19′ (FIG. 5( b)). In thismanner, the heat exchanger 16 can remain at the original position in thetank 10.

This applies to all connections between the heat exchanger 16 (orfurther line feedthroughs) and on-site installation parts locatedoutside of the tank 10 which require a feedthrough through the tank walland which cannot be accessed with tools, or can only be accessed withextreme difficulties (see the inaccessible connection 24 in FIG. 3( a)).Accessible connections (e.g. 25 in FIG. 3( a)) through which the heatexchanger 16 can be disconnected and dismantled “on the inside” are(normally, but not necessarily) implemented in the same manner; however,in this case, the line and the tube socket are not cut through, butremain in the original condition.

The previous explanations apply analogously to the closure by metallicbonding in the case of a flange connection arranged on the tank 10 (seeflange connections 26 in FIGS. 3 and 26′ in FIG. 6). In this case too,opening is carried in detail in such a manner that the weld seam cansimply be “cut out” with sufficient material still remaining so that anew weld seam can be applied.

The flange connection 26 in the exemplary embodiment of FIG. 3 comprisesa flange 27 at the end of a tube piece protruding from the tank wall,which flange is closed through suitable screw connections with a cover28. As is apparent from the enlarged cut-out in FIG. 3( b), a socket 30facing towards the tank is welded to the flange 27. A cap 29 is welded(weld 31) to the free end of this socket, which cap, starting from theflange 27, encloses the flange connection 26 in a gas-tight manner. Inorder to remove the cap 29 and thus to get access to the flangeconnection 26 in the case of repair work or a check, the socket 30 andthe cap 29 are cut (severed) at a severing location 32 in such a mannerthat the section with the weld 31 falls off. The cap 29 can then beremoved and the flange connection 26 can be opened. If the flangeconnection 26 is subsequently to be closed again in a gas-tight manner,the cap 29 is attached and is connected at the severing location 32 tothe shortened socket 30 by a new weld 31′.

An alternative exemplary embodiment for such a flange cover isillustrated in FIG. 6. The flange showed 26′ therein is covered by a cap29′ that has a rim and is welded at the outer edge of the rim to aflange ring 37 (weld 35) which, in turn, is welded to the tube pieceprotruding from the tank wall. If the cap 29′ needs to be removed, theedge and the flange ring 37 are severed at a severing location 36 sothat the section with the weld 35 can be removed and the cap 29′ can betaken off. When closing at a later time, the flange 37 and the cap 29′are connected again in a gas-tight manner by a new weld 35′ (FIG. 6(b)).

With this kind of repair work, the tank 10, which is closed in a gas-and pressure-tight manner by means of firmly bonded connections betweenits parts, is closed again in a simple manner after the repair work.Since such a repair work and/or check is needed only very rarely, thisway of opening and closing again is safer and more cost-effective thanif sealed openings would be provided for this.

REFERENCE LIST

10 Tank

11 Interior

12, 13 Tank part

14, 15 Severing location

16 Heat exchanger

17, 18 Tube

19, 19′, 19″ Weld

20 Weld

21, 22 Tube socket

23, 23′, 23″ Severing location

24 Inaccessible connection

25 Accessible connection

26, 26′ Flange connection

27 Flange

28 Cover

29, 29′ Cap

30 Socket

31, 31′ Weld

32, 36 Severing location

33, 33′ Weld

34 Tube piece

35, 35′ Weld

37 Flange ring

28 Compressor

40 Refrigerating installation

KM1, KMn Refrigerating module

L, L′ Gap

SL1, SL2 Collecting line

1. A method for repairing and/or checking a refrigerating moduleaccommodated in a tank which is closed in a permanently pressure-tightmanner, wherein the refrigerating module comprises a closed localrefrigeration circuit with a compressor and a heat exchanger, the methodcomprising: cutting open the tank at at least one predetermined severinglocation, repairing and/or checking the refrigerating module located inthe tank, and closing the tank at the severing location (14, 15; 23,23′, 23″; 32, 36) by a firmly bonded connection.
 2. The method accordingto claim 1, wherein, the tank is severed in at least two separate tankparts, and that after the repair of the installation, the at least twoseparate tank parts are connected again to each other in a firmly bondedmanner.
 3. The method according to claim 2, wherein the at least twoseparate tank parts are welded together.
 4. The method according toclaim 1, wherein at least one tube is fed outward through the tank wall,wherein for feeding through the at least one tube, the tank has a tubesocket which protrudes outward from the tank wall and through which theat least one tube is fed outward, and the outside of the tube isconnected to the outer end of said tube socket in a pressure-tightmanner, wherein for repairing and/or checking the installation, the tubesocket with the tube placed therein is cut through at a firstpredetermined severing location, and that after the repair work and/orcheck, the tube socket is closed again in a pressure-tight manner by afirmly bonded connection with the pipe fed therethrough.
 5. The methodaccording to claim 4, wherein the at least one tube is connected by aweld on the outside of the tube in pressure-tight manner to the outerend of the tube socket, and wherein after the repair work and/or check,the tube socket is closed again in a pressure-tight manner by welding itto the tube fed therethrough.
 6. The method according to claim 4,wherein the at least one tube is cut through at a second severinglocation positioned outside the first severing location thereby forminga gap in the tube, wherein for closing the gap after the repair workand/or check, the cut-off tube coming out of the tank is first movedoutward through the tube socket such that it adjoins, at the secondsevering location, the tube part located on the outside, wherein the twoends of the tube are connected to each other, and wherein the tubesocket is closed again in a pressure-tight manner by a firmly bondedconnection with the tube fed therethrough.
 7. The method according toclaim 6, wherein the two ends of the tube are connected to each other bya weld.
 8. The method according to claim 6, wherein the at least onetube is connected to an installation part arranged in the tank, andwherein the tube is displaced together with the installation part. 9.The method according to claim 4, wherein the at least one tube is cutthrough at a second severing location positioned outside the firstsevering location and at a third severing location inside the tankthereby forming a gap, wherein after the repair work and/or check, asuitable tube piece is inserted into the gap for closing said gap and isconnected at the second and third severing locations to the ends of thetube, and wherein the tube socket is closed again in a pressure-tightmanner by a firmly bonded connection with the inserted tube piece. 10.The method according to claim 9, wherein the tube piece is connected bya weld to each of the ends of the tube.
 11. The method according toclaim 1, wherein on the tank, an outward-facing flange connection isarranged that has a flange which is closed by a cover attached thereon,wherein the flange connection is surrounded by a cap which is fastenedto the flange connection and closes the flange connection in apressure-tight manner with respect to the outside, wherein for repairingand/or checking the installation accommodated in tank, the cap is cutopen at a severing location, and wherein after completion of the repairwork and/or check, the cap is fastened again to the flange connection ina pressure-tight manner.
 12. The method according to claim 11, whereinthe flange is spaced apart from the tank wall, wherein a socketextending towards the tank is attached to the flange, wherein the cappulled over the flange connection and the socket is connected to thefree end of the socket in a firmly bonded manner, and wherein theconnection point is severed at the severing location by simultaneouslycutting through the cap and the socket.
 13. The method according toclaim 11, wherein the flange is spaced apart from the tank wall, whereinbetween the flange and the tank wall, a flange ring is attached thatextends parallel towards the flange, that the cap pulled over the flangeconnection is connected to the outer edge of the flange ring in a firmlybonded manner, and wherein the connection point is severed at thesevering location by simultaneously cutting through the cap and theflange ring.
 14. The method according to claim 11, wherein the cap isconnected by a weld to the flange connection, and after completion ofthe repair work and/or check, the cap is fastened again by a weld in apressure-tight manner to the flange connection.
 15. A tank, comprising arefrigerating module accommodated therein, wherein the refrigeratingmodule comprises a closed local refrigeration circuit with a compressorand a heat exchanger, wherein the tank is configured for carrying outthe method according to claim 1, and wherein the tank is closed in agas-tight and/or pressure-tight manner by means of firmly bondedconnections between its parts.
 16. The tank according to claim 15,wherein from the installation accommodated in the tank at least one tubeis fed outward through the tank wall, and wherein for feeding throughthe at least one tube, the tank has a tube socket which protrudesoutward from the tank wall and through which the at least one tube isfed outward, and the outside of the tube is connected to the outer endof said tube socket in a pressure-tight manner.
 17. The tank accordingto claim 16, wherein the at least one tube is connected by a weld on theoutside of the tube in a pressure-tight manner to the outer end of thetube socket.
 18. The tank according to claim 15, wherein on the tank, anoutward-facing flange connection is arranged that has a flange which isclosed by a cover attached thereon, and wherein the flange connection issurrounded by a cap which is fastened to the flange connection andcloses the flange connection in a pressure-tight manner with respect tothe outside.
 19. The tank according to claim 18, wherein the flange isspaced apart from the tank wall, wherein a socket extending towards thetank is attached to the flange, and wherein the cap pulled over theflange connection and the socket is connected to the free end of thesocket in a firmly bonded manner.
 20. The tank according to claim 18,wherein the flange is spaced apart from the tank wall, wherein betweenthe flange and the tank wall, a flange ring is attached that extendsparallel towards the flange, and wherein the cap pulled over the flangeconnection is connected to the outer edge of the flange ring in a firmlybonded manner.
 21. The tank according to claim 18, wherein the cap isconnected by a weld to the flange connection.